Reactors of the type under consideration herein generally serve for bringing a gas into intimate contact with a solid available as a bulk material in order to bring about a reaction and/or adsorption between gas and solid. Such reactors are utilized in the catalytic conversion of gases, in the adsorption of gases, or in fine dust filtering. In general, the bulk material is conducted through the reactor from the top toward the bottom while the gas is passed over the solid in a crosscurrent or countercurrent fashion. The countercurrent operation generally affords better contact and better distribution between the two phases and therefore is more effective, i.e., has a higher degree of efficiency. However, the practical realization of reactor installations of the type discussed above has met with considerable problems and thus far has not as yet been accomplished, at least not on an industrial scale.
A moving bed reactor of the aforementioned type has been known from German Laid-Open Patent Application No. 3,313,943, wherein the bulk material is introduced centrally into the reaction chamber by way of the first inclined sliding surface. After passing through the reaction chamber, the bulk material enters a regenerating device located therebeneath. The material is discharged from the regenerating device via a second sloping sliding surface and passes to the base of a vertical conveying shaft; in the latter, the material travels upwardly to the first inclined sliding surface. In many usages of such reactors, thus, for example, in removing pollutants from flue gases, the gas must be treated in multistage fashion in various reactors. First of all, the flue gas passes through at least one reactor wherein an SO.sub.2 cleaning step is performed. Only thereafter will NO.sub.x reduction take place in a further reactor stage. In industrial plants, such as power plants, for example, the volume stream of flue gas produced is so considerable that it can be treated in accordance with regulations only in parallel reactor stages. In these large-scale industrial uses, reactor systems must thus be provided which consist of several reactor modules serving for identical types of treatment as well as different-type treatments. A module-type combination of several moving bed reactors of the conventional type of structure is impossible, above all, for the reason that the devices for feeding, discharging, and conveying the bulk material cannot be connected in parallel and/or in series. Furthermore, the known reactors occupy a relatively large construction volume.